Charles allan jones



" Nrrnn STATES Parenti?` CHARLES ALLAN JONES, OF HATHERLEY COURT, GLOUCESTER, COUNTY OF GLOUCESTER, EGLAND.

STEP-LADDER.

O SPECIFICATION forming' part of Letters Patent No. 286,617', dated Cctober 16, 1883.

Application filed Dccemher), 1882. (No model.) Patented in England August 1G, 1392. No. 3593.

To @ZE whom t may concern,.-

Be it known that l, CHARLES ALLAN Jones,

pable of being spread apart, so as to form av Wide base for the apparatus when erected, and insure its stability Without supplement-ary snpport.

The objects of my improven ents are to secure lightness, compact-ness when folded up, and increased firmness and safety when extended for use.

Y In carrying out my invention each of the said principals may comprise a flight of steps but l usually prefer to adhere to the common practice of forming only one such principal, which I will call the front principal, as a flight of steps, and employing the other or 3o back principal as an inclined strut or support to the upper endrof, the front principal. 1n connecting these tivo parts together 1 adopt the following devices: Instead of hinging the upper end of the hack principal to the upper end ofthe front one, I arrange the said upper i end ofthe former to slide longitudinally on a guide strip or strips formed on or attached to thelatter. An equivalent mode of construction would consist in the use of pins Working .fio in slots or grooves. Although the principals are by preference tapered longitudinally, the guide-strips on each side of the front are adjusted parallel to each other. I further connect the two principals'hy means of a stretcher pivoted to the bottom of the back principal,

as to one end, and as to the other to the middle, or there-about, of the front principal. In

erecting and extending the apparatus for use the upper end of the hack principal slides on the guide strip orlstrips of the front princi- 5o pal until stops fitted to the respective parts arrive in contact with one another and arrest further motion. At the same time the stretcher before referred to vibrates about its pivoted ends until it arrives in such a position relative to the two principals that it serves not only as a. tie to prevent the farther spreading of their lower ends, but also becomes effective as a strut to prevent the accidental collapse ofthe apparatus ,in the event 6o of the user overhalancing himself in a forward direction. On the other hand, if the apparatus, when open, be tilted ou the foot of the front principal as apivot, collapse ensues, and the two principals and stretcher fold themselves compactly together.- The foot of each principal remains level, however, with the other, so that the apparatus, when folded, is still capable of standing erect. 1n constructing a principal comprising a iiight of steps I form 7o the sides thereof of bars braced diagonally, and connected by cross-pieces, on which latter the treads are mounted. The hack principal and stretcher are also, by preference, constructed of bars strutted, tied, and diagonally braced With a vienr to combining extreme lightness with adequate strength.

1n the accompanying` drawings illustrative of my said invention, Figure 1 represents in perspective a view of my improved portable Se .steps or selfsupporting ladders when folded together, and Fig. 2 shows the same apparatus when extended ready for use.

The front principal, A, is formed as a'light of steps, and the back principal, B, acts as an inclined strut or support to the upper end of the front principal when the apparatus is eX- tcnded for use, as in Fig. 2, and also serves as one of the feet to support the apparatus when folded and standing erect, as in Fig. l. The 9o upper end` ofthe front principal is fitted on each side with a guide-strip, l, for receiving a projection or pin, D, formed on or attached to the upper end of the back principal or leg, B, and stops E E are provided at the upper ends of the front and hack' principals, respectively, to limit the sliding motion referred to. The lower end of the hack principal or leg, B,

e l :escom is attached by means of a stretcher, F, to the y front principal at or Vabout the middle of its length. Each end of the stretcher is pivoted to the parts named, so as to be free to vibrate. The points of attachment for the two ends of the stretcher should be relatively such that whenvthe apparatus is extended for use the stretcher will assume an angle of about sixty degrees with the horizon, and also such that when the apparatus is folded and stood erect the lower extremities of both principals will be in the same horizontal plane. lf a more obtuse angle be employed, the stretcher will not act so effectively as a tie, and if the angle be made much more acute than that above recommended the sliding motion will be inconveniently extended, or the space occupied by the base of the apparatus undesirably reduced. The front principal is formed of bars a, braced by diagonals a', and connected by cross-pieces at, on which the treads (t3 are mounted. It Will be seen that the back principal and stretcher are somewhat similarly constructed of bars strutted, tied, and diagonally braced.

Figsf?) and 4 represent in elevation and horizontal section. respectively, and to an enlarged scale, the manner in which l construct the sliding end of the leg B and the guide C. Aplate attached by screws or otherwise to the leg B carries a pin, D, projecting` in front of and in contact with the guide-strip C, or the side of the front principal, if preferred. The back principal or leg, B, thus grasps the guide C between the pin D and the stop-piece E; but it is obvious that a similar result might be attained by a pin working in a slot, or by other equivalent mechanical means. y

Having now described the nature of my said invention and the manner in which' the same is or maybe carried into effect, I would have it understood that I neither confine myself to the precise details hereinbefore described, and illustrated on the accompanying drawings,

nor to the proportions of the various parts of 45V the apparatus portrayed, as many of these may be modified or varied without departing from the principal of my invention; but

Vhat l consider to possess novelty and utility, and therefore claim, as my invention, and wish to secure by Letters Patent, is-y 1. The portable steps or self-supporting ladders, consisting of two principals, A B, connected at their upper ends by a sliding joint, and controlled as to their lower ends by a stretcher, F, which, in certain positions of the apparatus, operates as/a tie and in others as a strut, substantially as described. t

2. The step-ladder herein described, consisting of the front principal, A, having guiderail C and cross-bar E, the'back principaLB, having stop-piece E adapted to slide along the back surface of the guide C and engage under the bar E when the device is in operation, and having also the pins D for holding the back principal in connection with the said guide, and the whole combined and operating substantially as and for the purposes set forth.

CHARLES ALLAN JONES.

die. 

